Well, with a heavy lance, a rouncey, warspear, and light (cloth) armour and a weak shield, it's quite upkeepable. If I put on mail + helm + gauntlets + boots, then not so upkeep-friendly.
I roll as infantryman on town maps with cloth armour and a warspear, that fills up the wallet.
Bumpslashers must be hurting though, since people generally are more watchful for cavalrymen and we see more polearms these days, and the horses which you can upkeep are quite fragile beasts. HAs probably, too, but I feel no pity for them (and they are the most effective way to dismount other horsemen, anyway). But it is nice, on the other hand, to see only a handful of horsemen on a map instead of 20 horses on every side.